We have some boxes running Windows XP for an automated production process. I (not me personally but a robot) connect new USB devices to these boxes. There is a device driver for this device type and it's loaded after connecting a device and running like a charm.
But ... it takes about 8 to 10 seconds after pluging in a new device until it is accessible. When I connect an already previously seen device again it only takes 3 seconds. The driver has a catalog file. It's not signed by Microsoft WHQL but uses a test certificate we have installed on the machines.
There is only one inf/pnf file to be considered and so I wonder why it takes so long to detect a new device, create the information in the registry and load the driver. Time is money and so I need to speed up the process.
Any hints for me? Especially does somebody know that WHQL-certified drivers are recognized more quickly by Windows / device manager?
These devices have unique serial numbers, correct? That's part of what Windows uses to create the per-instance data necessary to track whether it's seen this device before. In the case where you plug in a device that's already seen before, Windows will pick up the old instance data and load the appropriate driver. If you plug in a device that Windows has never seen before (e.g. same VID/PID but different serial number), it needs to go through the process of creating registry entries, parsing the INFs to find the correct driver, etc.
Are you sure those devices that show up quickly with WHQL'd drivers have never been attached to the system before? Also, are these systems configured to connect to Windows Update to look for drivers when a new device is attached? It's definitely true that Windows will prefer a WHQL'd driver over an unsigned (or self signed) package, so it's possible that Windows is trying hard to find something else before defaulting to your self signed driver.
-scott